A variety of multi-walled carbon nanotubes grafted with immidazolium-based ionic liquids (CNT-ILs) were synthesized and utilized as highly efficient heterogeneous catalysts for the production of cyclic carbonates via cylcoaddition reactions of epoxides and CO2. In comparison with conventional heterogeneous catalysts that employ porous silica and polymer supports. CNT-ILs exhibited significantly enhanced catalytic reactivity towards the cycloaddition reactions. The effects of the IL molecular structure (alkyl chain length and counter anions) and the reaction parameters (temperature. CO2 pressure, and time) on the catalytic performance of the corresponding heterogeneous catalysts were also systematically investigated. (C) 2012 Elsevier B.V. All rights reserved.